Air conditioning system and valve used therein



Jan. 24, 1967 D. R. GRAHL 3,300,132

AIR CONDITIONING SYSTEM AND VALVE USED THEREIN Filed Sept. 28, 1964 INVENTOR.

BY DARW/N 1? 6mm United States Patent 01 3,300,132 AIR CONDITIONING SYSTEM AND VALVE USED THEREIN Darwin R. Grahl, Lincoln Park, Mich., assignor to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Sept. 28, 1964, Ser. No. 399,509 2 Claims. (Cl. 236-1) This invention relates to air conditioning systems having individual room heat exchangers supplied with hot and cold heat exchange fluids from a central heater and a central cooler. Water is the usual heat exchange fluid.

One object of the present invention is to provide an air conditioning system wherein the hot and cold fluids are directed through separate paths, thereby minimizing losses in capacity which would occur if the fluids were allowed to intermingle.

Another object is to provide an air conditioning system wherein a single temperature sensor in each room area is effective to control both the heating fluid and the cooling fluid supplied to that area.

A further object is to provide an air conditioning system wherein each room area is serviced by a single valve mechanism which controls both the heating fiuid and the cooling fluid supplied to that area.

Other objects of this invention will appear from the following description, accompanying drawing, and appended claims.

In the drawing the single figure is a diagrammatic illustration of an air conditioning system embodying the invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

In the drawings there is shown a commercial air conditioning system comprising a central boiler or water heater and a central water cooler or chiller 12. Connected with heater 10 is a main hot water delivery line 14 and a main hot water return line 16. Each room area serviced by the system is provided with one or more room heaters 18 which are connected to main line 14 by a supply branch 20 and to main line 16 by a return branch section 22.

Connected with central cooler 12 is a main cold water delivery line and a main cold water return line 17. Each room area serviced by the system is provided with one or more room coolers 24 which are connected to main line 15 by a supply branch section 26 and to main return line 17 by a return branch section 28. Each of the main supply lines is provided with a continuously operating pump 19.

The drawing illustrates two room heaters and two room coolers. However it will be appreciated that in practice any number may be provided in accordance with the number of rooms in the hotel, oflice building, hospital, or the like being serviced by the system. The heating fluid is preferably hot water, although steam can be employed; the cooling fluid is preferably cold water. It will be noted that the hot water circuit is entirely separate from the cold water circuit so that the two fluid streams never intermingle with one another in a manner to diminish their respective heating or cooling capabilities.

Each room conditioner 18 or 24 is provided with a control valve 30 which includes a brass housing 32 having a hot inlet 34, cold inlet 36, hot outlet 38, and cold outlet 3,300,132 Patented Jan. 24, 1967 ice 40. Communicating with inlet 34 is avalve seat 42 which cooperates with a spherical val-ve element 44 carried by stem 46. Communicating with cold inlet 36 is a valve seat 48 which cooperates with a spherical valve'element 50 carried by a stem 52. A compression spring 45 biases valve element 50 against seat 48. Stem 52 for element 50 includes a circular upper portion 47 which projects through a seal 49 in partition 51; a suitable seal may be formed from molded polytetrafluoroethylene containing asbestos fibers. Stem 46 for element 44 is of non-circular cross section and projects through aligned circular openings in a partition 54; a compression spring 55 within the partition urges the stem and valve element upwardly into engagement with a lever operator 56.

Operator 56 comprises two levers 58 and 60 having central overlapped portions located on opposite faces of a piston 62 which is slidably mounted in a cylindrical bore 64 of housing 32. A pivot pin 66 extends through piston 62 and the overlapped portions of levers 58 and 60 so that each lever can move independently about the pin without interferring with vertical movement of the piston. The arrangement is similar to that shown in US. Patent 2,805,025.

Lever 58 carries a thermostatic power element 65 of the type shown in US. Patent 2,636,776. The piston 67 of the power element engages lever 60 so that thermal expansion of the wax charge in element 65 is effective to force the right end portions of levers 58 and 60 apart. Thermal contraction of the Wax charge permits compression spring 68 to force the right end portions of levers 58 and 60 toward one another. Of course, as the right portions of the levers move toward one anotherthe left portions move apart in a scissors-like action about pivot 66. A reverse motion occurs as the right'portions of the levers separate. Piston 62 is carried by the piston 70 of a conventional thermostatic power means 72 which is powered by thermostatic fluid in a remotely positioned bulb 74. In a normal installation the bulb is positioned at the inlet of the room conditioner which houses heater 18 and cooler 24. Bulb 74 thus responds to the need for conditioning by forcing piston 70 downwardly on bulb temperature increase.

In the illustrated valve spring 45 is stronger than spring 55. However when valve element 50 engages seat 48 spring 45 is suflicient to move pistons 62 and 70 upwardly in response to thermal contraction of the fluid contained within bulb 74 and capillary 76. As shown, both valve elements 44 and 50 are closed and bulb 74 is satisfied. Bulb 74 calls for heat by contraction of its fluid such that spring 55 drives piston 62 and valve element 44 upwardly; valve element 50 remains closed against seat 48 during this period. Bulb 74 calls for cooling by expansion of its fluid such that piston 62 is driven downwardly to open valve element 50; valve element 44 abuts against seat 42 during this period.

To vary the temperature setting of the valve mechanism I may use any conventional arrangement, as for example the diagrammatically illustrated capillary and connected bellows 82 cooperating with a manual bellows volume adjustment screw 84. By adjusting screw 84 downwardly the volume of the thermostatic fluid system is reduced to lower the temperature setting of the valve. Adjusting screw 84 upwardly raises the temperature setting of the valve.

During the periods when bulb 74 calls for heat the operator chamber 78 above partitions 51 and 54 is heated by the hot fluid from line 20; the thermostatic fluid in capillary 76 and the chamber above piston 70 may become heated such as to tend to close valve 44. Power element 65 compensates for this tendency by expanding the right hand portions of levers 58 and 60 apart. Lever 60 maintains its illustrated position by reason of spring 45; the right hand portion of lever 58 is therefore given a slight upward bias to compensate for the downward bias due to the heating of the thermostatic fluid in capillary 76.

During the periods when bulb 74 calls for cooling the flow f coolant through brass housing 32 tends to cool the fluid in capillary 76 and the wax charge in power element 65; the power element will thus compensate for the fluid cooling by allowing spring 68 to apply a downward bias on valve element 50 in opposition to the upward bias provided by the cooling of the capillary fluid.

During the heating cycle bulb 74 works against a relatively weak spring 55, while during the cooling cycle the bulb works against a stronger spring 45. Power element 65 is therefore charged so that it expands somewhat during the changeover from cooling to heating. The power element thus reduces the temperature change necessary to proceed from cooling to heating and vice versa, all as more fully described in the above-mentioned US. Patent 2,805,025.

The present valve includes two separate inlets and two separate outlets for the respective hot and cold fluids; the fluids are thus supplied to separate heat exchangers 18 and 24 where they cannot interrningle to interfere with their heat exchange capabilities. The four pipe system having four main pipes 14, 15, 16 and 17 uses more piping than the conventional two pipe or three pipe systems; however, it eliminates some valving and the common return line wherein hot and cold fluids can intermingle such as to interfere with their heat exchange capabilities.

A major feature of the present invention is the employment of the illustrated valve wherein two separate fluid streams are controlled by a single temperature-responsive sensor 72. Such an arrangement eliminates the need for correlating two separate temperature sensors to provide alternate heating and cooling in the desired temperature ranges. The drawings show Valves 30 upstream from the heat exchangers 18 and 24. It is believed however that they could be arranged in downstream locations. The drawings show valve 30 having a seal 49 surrounding the cold valve element stem 52 for isolating the hot fluid path from the cold fluid path; however a seal could be provided around hot valve element stem 46 as an addition to or in lieu of seal 49.

What is claimed is:

1. An air conditioner valve comprising a housing having a hot liquid inlet and outlet defining a first flow path therebetween, a cold liquid inlet and outlet defining a second flow path therebetween; partition means within the housing completely isolating the first and second flow paths from one another, and cooperating with the housing in defining an operator chamber; a hot valve seat located in the first flow path; a cold valve seat located in the second flow path; a first valve element registering with the hot seat; a second valve element registering with the cold seat; a first stem extending from the first valve element through the partition means into the operator chamber; a second stem extending from the second valve element through the partition means into the operator chamber; an annular seal in the partition means surrounding at least one of the stems; temperature-responsive power means located to respond to the demand for hot or cold fluid, said power means having an output member movably located in the operator chamber; and a lever operator disposed in the operator chamber with its intermediate portion engaged with the output member and its opposite end portions engaged with respective ones of the valve element stems; said cold valve element being disposed between the cold inlet and cold seat, said cold valve element being spring-urged toward the cold seat, whereby the second stem acts as a fulcrum for the lever operator during movement of the hot valve element; said hot valve element being disposed between the hot valve seat and hot outlet, whereby the hot seat constitutes an abutment for causing the first stem to act as a fulcrum for the lever operator during movement of the cold valve element.

2. The valve of claim 1 wherein the partition means comprises two separate inserts removably locked in the housing, each insert having an opening therethrough for slidably accommodating one of the valve element stems.

References Cited by the Examiner UNITED STATES PATENTS 2,557,035 6/1951 Lichty 26 3,189,275 6/1965 Sorenson et al. 2361 MEYER PERLIN, Primary Examiner. CHARLES SUKALO, Examiner. 

1. AN AIR CONDITIONER VALVE COMPRISING A HOUSING HAVING A HOT LIQUID INLET AND OUTLET DEFINING A FIRST FLOW PATH THEREBETWEEN, A COLD LIQUID INLET AND OUTLET DEFINING A SECOND FLOW PATH THEREBETWEEN; PARTITION MEANS WITHIN THE HOUSING COMPLETELY ISOLATING THE FIRST AND SECOND FLOW PATHS FROM ONE ANOTHER, AND COOPERATING WITH THE HOUSING IN DEFINING AN OPERATOR CHAMBER; A HOT VALVE SEAT LOCATED IN THE FIRST FLOW PATH; A COLD VALVE SEAT LOCATED IN THE SECOND FLOW PATH; A FIRST VALVE ELEMENT REGISTERING WITH THE HOT SEAT; A SECOND VALVE ELEMENT REGISTERING WITH THE COLD SEAT; A FIRST STEM EXTENDING FROM THE FIRST VALVE ELEMENT THROUGH THE PARTITION MEANS INTO THE OPERATOR CHAMBER; A SECOND STEM EXTENDING FROM THE SECOND VALVE ELEMENT THROUGH THE PARTITION MEANS INTO THE OPERATOR CHAMBER; AN ANNULAR SEAL IN THE PARTITION MEANS SURROUNDING AT LEAST ONE OF THE STEMS; TEMPERATURE-RESPONSIVE POWER MEANS LOCATED TO RESPOND TO THE DEMAND FOR HOT OR COLD FLUID, SAID POWER MEANS HAVING AN OUTPUT MEMBER MOVABLY LOCATED IN THE OPERATOR CHAMBER; AND A LEVER OPERATOR DISPOSED IN THE OPERATOR CHAMBER WITH ITS INTERMEDIATE PORTION ENGAGED WITH THE OUTPUT MEMBER AND ITS OPPOSITE END PORTIONS ENGAGED WITH RESPECTIVE ONES OF THE VALVE ELEMENT STEMS; SAID COLD VALVE ELEMENT BEING DISPOSED BETWEEN THE COLD INLET AND COLD SEAT, SAID COLD VALVE ELEMENT BEING SPRING-URGED TOWARD THE COLD SEAT, WHEREBY THE SECOND STEM ACTS AS A FULCRUM FOR THE LEVER OPERATOR DURING MOVEMENT OF THE HOT VALVE ELEMENT; SAID HOT VALVE ELEMENT BEING DISPOSED BETWEEN THE HOT VALVE SEAT AND HOT OUTLET, WHEREBY THE HOT SEAT CONSTITUTES AN ABUTMENT FOR CAUSING THE FIRST STEM TO ACT AS A FULCRUM FOR THE LEVER OPERATOR DURING MOVEMENT OF THE COLD VALVE ELEMENT. 